The race to repeal Obamacare by President-elect Donald Trump and the Republican Congress will have one immediate side effect beyond any doctor's office: a large tax cut for the wealthiest Americans.

Urged on by Trump, the Senate overnight adopted a budget resolution that clears a path for eliminating the tax-and-spending provisions of the Affordable Care Act by simple majority vote — no Democratic cooperation required. That means repeal of two provisions targeted at high-income households: a 0.9 percent hospital insurance tax on earnings above $250,000 for couples and a 3.8 percent tax on capital gains, dividends and other nonlabor income above that same threshold.

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That would provide a tax cut averaging $7 million for each of the 400 highest-earning taxpayers, according to new calculations by the liberal Center on Budget and Policy Priorities using Internal Revenue Service data. That cut, the center estimated, would amount to $2.8 billion annually overall — or approximately the value of Obamacare subsidies for those with modest incomes in the 20 smallest states and the District of Columbia.

Overall, eliminating those two levies would represent a tax cut of roughly $346 billion over 10 years, according to the Congressional Budget Office. Households with million-dollar-plus incomes — a much larger group than the top 400 — would receive an average tax cut of $49,000 a year, the center says.

Democrats are certain to use this data to argue that repeal represents a betrayal of Republicans' commitment to lifting the economic fortunes of average Americans rather than the wealthy. A tax cut for the most affluent would also collide with the recent statement by Trump's nominee for Treasury secretary, Steven Mnuchin, about the new administration's tax-overhaul plans.

"Any reductions we have in upper-income taxes will be offset by less deductions so that there will be no absolute tax cut for the upper class," Mnuchin told CNBC. Even as tax overhaul proceeds on a slower timetable, expect that to resurface much sooner in the Obamacare debate.